In the drilling and completion industry, the formation of boreholes for the purpose of production or injection of fluid is common The boreholes are used for exploration or extraction of natural resources such as hydrocarbons, oil, gas, water, and alternatively for CO2 sequestration. To increase the production from a borehole, the production zone can be fractured to allow the formation fluids to flow more freely from the formation to the borehole. The fracturing operation includes pumping fluids, such as water, at high pressure and high rate towards the formation to form formation fractures. To retain the fractures in an open condition after fracturing pressure is removed, the fractures must be physically propped open, and therefore the fracturing fluids commonly include solid granular materials, such as sand, generally referred to as proppants.
In addition to proppants and water, other components of the fracturing fluid can include friction reducing additives to allow fracturing fluids and proppant to be pumped to a target zone at a higher rate and reduced pressure. The treatment design generally requires the fluid to reach maximum viscosity as it enters the fracture. The requisite viscosity is typically obtained by the gelation of viscosifying polymers and/or surfactants in the fracturing fluid. Such additives include synthetically produced and naturally occurring polymers. The selection of additives is based on a number of factors including the makeup of the formation, formation fluids, pumping configurations, and borehole temperatures. The additives can be provided as dry powders and subsequently hydrated at the fracturing site, which saves delivery costs, reduces cost of mixing slurry, and saves space by reducing a footprint required for the additives at the site.
The art would be receptive to improved apparatus and methods for hydrating additives used in the fracturing fluid.